1. Field of the Invention
The present invention relates to a fabricating method of an electronic device, and in particular to a method of fabricating silylation polyvinyl phenol (PVP) for a dielectric layer of an electronic device.
2. Description of the Related Art
Organic thin film transistors (OTFTs) have drawn considerable interest in the past due to their low weight, economical large area fabrication cost, simple fabrication method, thin profile, and mechanical flexibility. Thus, OTFTs are employed in disposable products, radio frequency identification (RFID), smart levels, smart tags or other devices. Coating or inkjet printing is used for OTFT fabrication. Interfaces between dielectric layers and organic semiconductor layers of OTFTs exhibit electron trapping behavior due to the existence of hydroxyl groups. Electron trapping behavior degrades electron mobility and raises transistor threshold voltage (Vt). Industrial OTFTs must have higher electron mobility and lower Vt. Thus, further investigation of dielectric materials for OTFTs is important.
Dissolving is another problem of an organic thin film and an organic solvent with strong polarity used in OTFT fabrication. Dissolving results in organic thin film damage, electron mobility degradation and raised Vt. Pursuit of a solution to the aforementioned dissolving problem is also important.
“A polymer high-k dielectric insulator for organic field-effect transistors” in Journal of Applied Physics 98, 156104 discloses a polymer dielectric layer which is made of poly(vinylidene fluoride) (PVDF) and its copolymer with trifluoroethylene (P(VDF-TrFE)) which has a measured relative dielectric constant of about 11. This ferromagnetic polymer for top gate organic thin film transistors suffers from a time difference between charge accumulation and release. This problem results in abnormal transistor switching at different operating voltages. The PVDF polymer also has a lower melting point (166° C.˜170° C.) than polyvinyl phenol (PVP), which has a 360° C. melting point. “Low-voltage organic field-effect transistors and inverters enabled by ultra thin cross-linked polymers as gate dielectrics” in Journal of Applied Chemical Society 2005, 127, 10388 discloses a cross-linked PVP. The cross-linked PVP, which is fabricated with a cross-linking reagent, such as C0, C6 or C12, is used as a gate dielectric layer for low-voltage organic field-effect transistors and inverters.